Diesel engines configured for bi-fuel operation utilize an air and natural gas mixture along with diesel fuel. The advantages associated with bi-fuel operation include reduced diesel fuel consumption and reduced noxious emissions.
Conversion of a conventional diesel engine for bi-fuel operation is readily and typically accomplished by coupling a natural gas supply line to diesel engine's air intake line. To control the amount of natural gas introduced into the air intake, some type of conventional valve is disposed in the gas supply line. While a simple valve is preferred for robustness and cost, these valves do not typically offer the kind of precise adjustability required for efficient bi-fuel operation at a variety of diesel engine speeds.